This invention relates generally to apparatus for dampening the motion of a first member relative to a second member during rotation of the first member with respect to the second member. More particularly, the invention relates to a motion dampener which is relatively small in size and which retards the rotatable member with torque of relatively small magnitude.
Many miniature motion dampeners of the foregoing type rely on the coaction of a rotary impeller with a viscous material (e.g., a heavy grease) contained in a housing. As the impeller rotates, it shears through the viscous material so as to apply a retarding torque to the impeller. A major disadvantage of motion dampeners of this type is that the viscous material tends to leak from the housing unless rather costly steps are taken to completely seal the housing.
Other relatively small motion dampeners operate "dry" and simply rely on the force of one member against another to apply a retarding torque to the rotatable member. Prior dampeners of this type tend to be somewhat complex and most are incapable of applying a constant retarding torque to the rotatable member throughout the range of movement of the member. Moreover, many of the so-called dry dampeners still require some amount of lubricant for the components.